Yoo Chanyoung, Kim Woohyun, Jeon Jeong Woo, Park Eui-Sang, Ha Manick, Lee Yoon Kyeung, Hwang Cheol Seong
Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826, Republic of Korea.
ACS Appl Mater Interfaces. 2020 May 20;12(20):23110-23118. doi: 10.1021/acsami.0c03747. Epub 2020 May 7.
An ovonic threshold switch (OTS) based on amorphous chalcogenide materials possesses several desirable characteristics, including high selectivity and fast switching speed, enabling the fabrication of one selector-one resistor (1S-1R) crossbar array (CBA) for random access memory. Among the several chalcogenide materials, GeSe offers high selectivity and a strong glass-forming ability with environment-friendly, simple binary composition. In this report, the GeSe thin films were deposited via atomic layer deposition (ALD) using Ge(N(Si(CH))) and ((CH)Si)Se for its envisioned application in fabricating three-dimensional vertical-type phase-change memory. Highly conformal GeSe films were obtained at a substrate temperature ranging from 70 to 160 °C. The unique deposition mechanism that involves Ge intermediates provided a way to modulate the composition of the Ge-Se films from 5:5 to 7:3. Low threshold voltages ranging from 1.2 to 1.4 V were observed depending on the composition. A cycling endurance of more than 10 was achieved with the GeSe composition with 10 half-bias nonlinearity. This work presents the foundations for the future development of vertical-type 1S-1R arrays when combined with the ALD technique for GeSbTe phase-change materials.
基于非晶硫属化物材料的双向阈值开关（OTS）具有几个理想特性，包括高选择性和快速开关速度，这使得能够制造用于随机存取存储器的一选通器一电阻器（1S-1R）交叉开关阵列（CBA）。在几种硫属化物材料中，GeSe具有高选择性和很强的玻璃形成能力，且其成分简单、环境友好。在本报告中，使用Ge(N(Si(CH)))和((CH)Si)Se通过原子层沉积（ALD）来沉积GeSe薄膜，以用于制造三维垂直型相变存储器的预期应用。在70至160°C的衬底温度范围内获得了高度保形的GeSe薄膜。涉及Ge中间体的独特沉积机制提供了一种将Ge-Se薄膜的成分从5:5调节到7:3的方法。根据成分不同，观察到阈值电压低至1.2至1.4V。具有10倍半偏置非线性的GeSe成分实现了超过10次的循环耐久性。这项工作为与用于GeSbTe相变材料的ALD技术相结合的垂直型1S-1R阵列的未来发展奠定了基础。
